Device for representing relief items

ABSTRACT

An apparatus for conveying information includes a perforated plate having a plurality of circular openings; at least one pin (5, 15, 25, 25, 35, 45, 55, 65, 75, 85) which is axially movable to project through and above a respective circular opening, an electromagnetic actuator (6, 16, 66, 116) for moving the pin (5, 15, 25, 25, 35, 45, 55, 65, 75, 85), and a permanent magnet for retaining the pin in at least two stable positions.

FIELD OF THE INVENTION

The invention relates to a device for representing relief items whichincludes a perforated plate and at least one pin which is axiallymovable in one of the perforations in the plate to be detected. Suchdevices are used in particular as display devices which are detectablein a tactile manner, with the help of which blind persons can detectinformation. Generally, braille printing is used in which every letterof the alphabet is represented by a matrix of 2×3 or 2×4 dots which areplaced or not placed. The placement of a dot occurs in such a way thatthe pertinent pin is moved out of the corresponding drilling, as aresult of which it can be detected with the fingers. However, theinvention relates similarly to graphical display devices with whichrandom patterns, images or displays can be reproduced in a manner so asto be detectable in a tactile way. In such displays it is also possibleto provide different positions of the pins, so that relief-likerepresentations are possible. The important aspect is that therepresentation is transient, which means that the display can be changedat will.

STATE OF THE ART

Display devices are known in which the position of each pin is stable,which is effected in such a way for example that this pin is pressed bya spring against a stop. By activating an actuator such as anelectromagnet it is possible to bring this pin into its other position,i.e. it can be extended. As long as this pin is extended it is necessarythat the actuator exert pressure on the pin to hold it in this position.Such devices have a high power consumption and the occurring thermalproblems cause a complex production and arrangement of these devices.

Furthermore, display devices are known which provide a locking devicewhich holds the associated pin in its position which is not stable perse. Such devices are highly complicated from a mechanical viewpoint,complex in production and susceptible to faults.

It is the object of the present invention to avoid such disadvantagesand to provide a device of the kind mentioned above which comes with asimple arrangement, provides a low power consumption and neverthelessguarantees sufficient holding forces for each pin, thus allowingdetection with the finger without giving rise to the danger thatindividual pins are thus brought into another position, resulting in afalsification of the represented information.

BRIEF OUTLINE OF THE INVENTION

These objects are achieved by a device wherein each pin is provided witha position in which the tip of the pin is substantially arranged in theplane of the surface of the perforated plate and a further position inwhich it projects outwardly to such an extent that it is clearlyscannable by the finger of the user. If, as mentioned above, arelief-like display is necessary there are additional further positionsin which the pin projects to a different extent. The important aspect isthat the pin is held in each of the stable positions by magnetic forcesof attraction. These can occur between a permanent magnet and a part ofsoft iron or also between two permanent magnets which are polarisedcorrespondingly.

It has proved to be particularly advantageous to provide axiallymagnetisable segments in each pin. A pertinent perforated plate acts asa magnetic yoke in order to bring about a closed magnetic circulation.In this way it can be achieved that the pin is held in its stablepositions only by the magnetic forces. Despite the stability of theposition it is still provided with a certain resilient mobility in theaxial direction. This has proved to be a feature which is particularlyappreciated by users and enhances the operating convenience.

In a particularly preferable embodiment of the present invention it isprovided that each pin is provided with at least two, preferably threesegments which are permanently magnetised in the axial direction and arearranged flush behind one another in the axial direction and areseparated from one another by soft iron segments. The magnetisedsegments are magnetised alternatingly opposite to one another. A softmagnetic perforated plate is provided which in the zone of each pin isprovided with two annular recesses which are arranged in such a way thatat least in one stable position of the pin two magnetic segments of theassociated pin are substantially arranged in the centre of the twoannular recesses. This leads to a particularly strong holding force inthe extended position of the pins, so that in this position twopermanently magnetised segments form two magnetic circulations. Thethird permanent magnet is used to receive the forces of theelectromagnetic actuator.

The deletion of the entire display is a frequently occurring process inany kind of display device. This process can be simplified andaccelerated in such a way that a common actuator is provided which actsupon all pins simultaneously.

A particularly preferable embodiment of the invention consists of thefact that the perforated plate is arranged as the face surface of acylindrical disc, with the individual pins being arranged on concentriccircles. When this disc is rotated about its central point, thecharacters represented by the pins glide below the stationary hand ofthe user according to the rotation. This provides a particularconvenience in the use of the device.

SHORT DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows an axonometric representation of a device inaccordance with the invention;

FIG. 2 shows a partial sectional view along a plane according to lineII--II in FIG. 1 which is established by the axes of a part of the pins;

FIG. 3 shows a further embodiment of the invention in a sectional view;

FIG. 4 shows a third embodiment of the invention in a sectional view;

FIG. 5 shows a fourth embodiment of the invention in a sectional view;

FIG. 6 shows an altered arrangement of the pins;

FIG. 7 shows a top view of an embodiment of the device in accordancewith the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The device 1 in accordance with the invention as schematically shown inFIG. 1 is connected to a computer 3 by way of a cable 2. It controls thedevice 1 as an output unit such as a screen. The computer 3 canrepresent the control device in this respect.

FIG. 2 shows a first embodiment in a more detailed partial sectionalview. The top cover of the device 1 is formed by a perforated plate 4,through which project the pins 5, 15 and 25. Each pin 5, 15, 25 consistsof a head 5a, a projection 5b, an upper shaft segment 5c, a first softiron segment 5d, a first permanent magnet 5e, a second soft iron segment5f, a second permanent magnet 5g, a third soft iron segment 5h, a spacerelement 5i, a third permanent magnet 5j and a lower shaft segment 5k.These parts are arranged behind one another in the axial direction andare mutually connected by gluing, for example. The head 5a, theprojection 5b, the spacer element 5i as well as the upper and the lowershaft segment 5c and 5k are made from non-magnetic material, e.g.plastic or non-ferrous heavy metal. The parts below the projection 5bare additionally enclosed by a sleeve 51 which is also made from plasticor non-ferrous heavy metal. As is shown in FIG. 2 by arrows, the firstpermanent magnet 5e and the third permanent magnet 5j are magnetised inthe same direction, whereas the second permanent magnet 5g is polarisedin the opposite direction.

The pins 5, 15 and 25 are movable in the axial direction between two endpositions. In the upper end position the projection 5b rests on thelower side of the perforated plate 4 and a certain initial tension isproduced by the magnetic force. In an alternative embodiment it may beprovided, however, that a certain gap exists between the projection 5band the perforated plate 4 in the upper end position, so that the pin 5,15, 25 can move freely around its end position to a certain extentwithout leaving it. The soft magnetic perforated plate 7 is made up of amagnetisable material such as soft iron. Two annular recesses 7a and 7bare provided in the zone of each drilling of the perforated plate 7,which recesses are delimited by projections 7c, 7d and 7e. The distancebetween the projections 7c and 7d as well as 7d and 7e in the axialdirection substantially corresponds to the distance between the firstsoft iron segment 5d and the second soft iron segment 5f and between thesecond soft iron segment 5f and the third soft iron segment 5h. Theamount of possible axial displacement of the pins 5, 15 and 25 isadjusted in such a way that in the upper end position, which isrepresented in FIG. 2 by the pins 5 and 15, two magnetic circulationsare formed. The first permanent magnet 5e forms a magnetic circulationaround the annular recess 7a and the second permanent magnet 5g forms amagnetic circulation around the second recess 7b. In the lower endposition, which is represented in FIG. 2 by pin 25, the first permanentmagnet 5e forms a magnetic circulation around the second recess 7b.

The soft iron segments 5d and 5f are situated approximately at the samelevel and opposite to the projections 7c, 7d and 7e in the two endpositions. Any movement of the pin in the axial direction increases themagnetic gap between these parts and is therefore only possible againstthe resistance of the magnetic forces. That is why the pins 5, 15 and 25are kept in these positions in a stable manner.

An electromagnet 6 is provided below the soft magnetic perforated plate7 in the zone of each pin 5, 15, 25, as a result of whose activation thethird permanent magnet 5j can be attracted or repelled. It is thereforepossible, by a respective control of these electromagnets 6, to bringthe pins 5, 15, 25 into the respective other position.

FIG. 3 shows a simplified embodiment of the invention. Permanent magnets8 are attached at the lower side of the pins 35 and 45. A soft magneticperforated plate 17 limits the movement of the pin in the upper endposition of pin 35. As a result of the respective force of attractionthis position is stable. The permanent magnet 8 is attracted and tightlyheld by a soft iron plate 27 in the lower end position of pin 45. Anelectromagnet 16 is provided below the soft iron plate 27 forcontrolling the pin 35, 45.

FIG. 4 is an extension of the embodiment of FIG. 3, in which the module,consisting of the pins 35, 45 plus permanent magnet 8 of perforatedplate 4 and the soft magnetic perforated plate 17, is movably arrangedin a direction parallel to the surface of the perforated plate 4. Thismovement can be translational or rotational. A cover plate 9 is providedabove the pins 35, 45 which is provided with a reading window 9a throughwhich the position of a part of the pins 35, 45 can be scanned. The "nonvisible" pins below the cover plate 9 are always in their upper endposition in this embodiment. Conversely, the device can also be arrangedin such a way that the pins are brought to their lower end positionafter leaving the reading window. Before a pin reaches the readingwindow 9a, it is pulled downwardly by electromagnet 16, if necessary. Incase of a movement of the pins in the direction of arrow A this meansthat the pin 135 is optionally to be pulled downwardly by theelectromagnet 16, and retained in a downward position by soft iron plate37. After leaving the display window 9a the pin 235, if it were in thelower end position, could be brought back again to its upper endposition by the soft iron plate of electromagnet 116. This, however, isnot necessary because a wedge-like ramp 10 is provided whichautomatically brings the pins which are situated in their lower endposition into the upper end position. The electromagnet 116 is relevant,however, when the perforated plate 4 is to be moved in the oppositedirection, against the arrow A. As a result of this embodiment it ispossible to actuate a plurality of pins with only one or twoelectromagnets 16, 116.

FIG. 5 shows an embodiment which represents a modification of theembodiment of FIG. 2, but which is substantially simplified. The pin 55consists of a tip 55a made from plastic, an upper soft iron segment 55b,a permanent magnet 55c, a lower soft iron segment 55d and a shaft 55e.Only one single perforated plate 57 is provided whose surfacesimultaneously forms the top cover of the device. The upper soft ironsegment 55b is arranged in the upper end position opposite to aprojection 57a of the perforated plate 57. In the lower end position thelower soft iron segment 55d is arranged opposite to a projection 57d ofthe perforated plate 57. An electromagnet (not shown) for actuating thepins 55, 65 is provided below the perforated plate 57. The recesses 57band 57c are used for producing the magnetic circulations such as in theembodiment of FIG. 2.

FIG. 6 shows a further embodiment wherein the pins 65 are provided withat least one magnetic segment 61. Furthermore, magnetic plates 62 and 63are provided which cooperate with the magnetic segment 61. In thisembodiment the magnetic segment 61 can be permanently magnetic and themagnetic plates 62 and 63 can be soft magnetic or vice-versa. It is alsopossible that all these parts can be permanent magnets. In this case itis important that the forces acting in the end positions are forces ofattraction. The direction of magnetisation can be transverse to theaxial direction of the pins 65.

FIG. 7 shows a particularly ergonomic embodiment of the invention. Theactuation of the pins 75 (set) and 85 (not set) can occur in accordancewith one of the modifications as described above. A support surface 70is provided on the upper side of the device for the hand of the user,with a cover 79 being provided on its circumference. This cover 79 isprovided with a display window 79a in the form of a segment of anannulus. Below the cover 79 a perforated plate 4 is rotatably arranged.Pins 75, 85 project through its drillings. The condition of the pins 75,85 can be scanned in the area of the display window 79a. Otherwise theyare covered by the cover 79. In this manner the information to be readslides under the substantially unmoved hand of the user. It may beprovided that the speed of rotation of the perforated plate 4 can beinfluenced by the user.

What is claimed is:
 1. An apparatus for representing relief items,comprising:a first perforated plate which is rotatable about an axialcenter thereof and which defines an upper surface and a plurality ofcircular openings therethrough arranged in concentric radial circles, acover plate positioned above said perforated plate, said cover plateproviding a reading window therein for exposing a portion of saidperforated plate therebelow, a pin which is mounted beneath saidperforated plate and rotatable therewith, said pin being axially movablebetween a first position wherein an upper end thereof is positionedbelow said upper surface of said perforated plate and a second positionwherein said upper end thereof is positioned above said upper surface ofsaid perforated plate, a permanent magnet for retaining said pin in oneof said first and second positions, and an actuator located beneath saidperforated plate for moving said pin between said first and secondpositions when not exposed by said reading window.
 2. An apparatusaccording to claim 1, wherein said actuator comprises an electromagnet.3. An apparatus according to claim 1, wherein said actuator comprises awedge-shaped ramp.
 4. An apparatus according to claim 1, including aspring which moves said pin in an axial direction thereof.
 5. Anapparatus according to claim 1, wherein said pin includes a permanentmagnet and wherein said actuator comprises a second perforated platewhich is magnetic and cooperates with said permanent magnet of said pinto axially move said pin.
 6. An apparatus according to claim 1,including a respective pin for each circular opening in said perforatedplate.
 7. An apparatus according to claim 1, wherein said actuatorcomprises a carriage which is movable transversely to an axis of saidpin to move said pin to a specific position.
 8. An apparatus forrepresenting relief items, comprising:a first perforated plate which isrotatable about an axial center thereof and which defines an uppersurface and a plurality of circular openings therethrough arranged inconcentric radial circles, a cover plate positioned above saidperforated plate, said cover plate providing a reading window thereinfor exposing a portion of said perforated plate therebelow, a pin whichis mounted beneath said perforated plate and rotatable therewith, saidpin being axially movable between a first position wherein an upper endthereof is positioned below said upper surface of said perforated plateand a second position wherein said upper end thereof is positioned abovesaid upper surface of said perforated plate, a permanent magnet forretaining said pin in one of said first and second positions, and anactuator located beneath said perforated plate for moving said pinbetween said first and second positions when not exposed by said readingwindow, said actuator comprising an electromagnet to move said pin fromsaid second position to said first position and a wedge-shaped ramp tomove said pin from said first position back to said second position.